Trocar set

ABSTRACT

A trocar set includes a handle portion, a first sleeve, a second sleeve, a gas tight assembly, and a pull band. A connection part of the handle portion extends from a grip and includes an assembling channel. The first sleeve includes an assembling end, a sleeving end, a first outer sleeve wall, and a fastening component. The assembling end is assembled to the assembling channel, and the fastening component is disposed at the sleeving end and contacts the first outer sleeve wall. A sleeving end of the second sleeve is inserted into the receiving end, and the second inner sleeve wall contacts the fastening component. A gas tight sleeve of the gas tight assembly encloses the receiving end and the blocking component. An outer wall of the gas tight sleeve is provided with a plurality of crossing channels. The pulling band crosses the crossing channel.

CROSS-REFERENCE TO RELATED APPLICATION

This non-provisional application claims priority under 35 U.S.C. §119(a) to Patent Application No. 105139683 filed in Taiwan, R.O.C. onDec. 1, 2016, the entire contents of which are hereby incorporated byreference.

BACKGROUND Technical Field

The instant disclosure relates to an instrument of minimally invasivesurgery and, more particularly, to a trocar set.

Related Art

In modern surgery, a trocar, instead of a surgical knife, can be used tocut an opening on a human body for a doctor to perform an operation suchas burning or cutting an internal tissue by medical instruments such asan optical fiber, an endoscope, or a laser. By way of the operations,wounds caused by the operation are smaller, pains patients feel areless, time for patients' lying in bed and rest after operations isshorter, and scars are smaller. Due to the small wounds and quickrecoveries, the kind of operations is called minimally invasive surgery.

A trocar is a combination of a cutlery and a trocar set. The trocar setincludes a long tube. The cutlery is fixed in the trocar set along thelong tube. After the cutlery is used to cut an opening on a human body,the cutlery is removed from the long tube of the trocar set. Next,surgical instruments such as an optical fiber, an endoscope, or a lasercan be inserted into the human body along the long tube to performoperations such as burning or cutting tissues.

During an operation stage, the length of the trocar set outside thehuman body is longer than that inside the human body. During either aninstrument inserting stage or the operation stage, it is easily happenedthat the medical professionals have physical contact with the trocar setoutside the human body. As a result of the trocar set being contacted,the wound may be enlarged, and patients may have greater pain intensity.

SUMMARY

To address the issue of prior art, the instant disclosure provides atrocar set. The length of the trocar outside the human body during anoperation can be shortened, which is beneficial to perform theoperation. The trocar set comprises a handle portion, a first sleeve, asecond sleeve, and a gasbag. The handle portion comprises a grip, aconnection part, and a first gas valve. The connection part extends fromthe grip and comprises an assembling channel The first gas valve isconnected to the connection part and communicates with the assemblingchannel. The first sleeve comprises an assembling end and a sleevingend. The assembling end is assembled to the assembling channel andcorresponding to the first gas valve. A sleeve wall of the sleeving endis provided with at least one first opening. The second sleeve isretractably connected to the sleeving end of the first sleeve. A sleevewall of the second sleeve is provided with at least one second opening.The gasbag is connected to an end of the second sleeve away from thefirst sleeve and corresponds to the second opening. The second sleeve iscapable of being retracted relative to the first sleeve such that thefirst sleeve can be received in the second sleeve, and the total lengthof the first sleeve and the second sleeve can be shortened.

In an embodiment, the first sleeve further comprises a first innersleeve wall and a first outer sleeve wall. The first sleeve defines afirst sleeve wall region and a second sleeve wall region. The firstouter sleeve wall surrounds an exterior of the first inner sleeve wallin the first sleeve wall region. The first outer sleeve wall does notsurround the exterior of the first inner sleeve wall in the secondsleeve wall region. The first opening is disposed on the first outersleeve wall.

Additionally, the second sleeve further comprises a second inner sleevewall and a second outer sleeve wall. The second sleeve defines a thirdsleeve wall region and a fourth sleeve wall region. The second outersleeve wall surrounds an exterior of the first outer sleeve wall in thethird sleeve wall region. The second outer sleeve wall surrounds anexterior of the second inner sleeve wall in the fourth sleeve wallregion. The first opening is disposed on the first outer sleeve wall,and the second opening is disposed on the second outer sleeve wall.

Additionally, a gas flow channel is formed between the first innersleeve wall and the first outer sleeve wall, between the first opening,the first outer sleeve wall, and the second outer sleeve wall, andbetween the second outer sleeve wall and the second inner sleeve wall,and communicates with the second opening. After gas flows through thefirst gas valve, the gas flows along the gas flow channel and enters thegasbag through the second opening to have the gasbag inflated. Thetrocar set can be fixed to a human body by the gasbag.

In an embodiment, the trocar set further comprises a gas tight assembly.The gas tight assembly is disposed on a part of the first outer sleevewall and the second outer sleeve wall and seals a portion where thefirst sleeve is connected to the second sleeve. In other words, the gasis restricted in the first sleeve and the second sleeve by the gas tightassembly to prevent a gas leak. Particularly, the gas inflated throughthe first gas valve can be restricted in the gas flow channel

Additionally, the gas tight assembly further comprises a blockingcomponent and a gas tight sleeve. The blocking component is assembled tothe first sleeve and is adjacent to the sleeving end. The gas tightsleeve is connected to a portion where the first sleeve is connected tothe second sleeve. The gas tight sleeve encloses the blocking component.As a result, the second sleeve moves away from the handle portion whenthe second sleeve is stretched, and a maximum stretching length is metwhen the second sleeve is stretched to contact the blocking component.It can be ensured that when the second sleeve is stretched, the gaswon't leak based upon the gas tight ability of the gas tight sleeve.

Additionally, the trocar set further comprises a gas tight ring. The gastight ring is connected to a part of the first sleeve and contacts asurface of the blocking component. The gas tight ring is enclosed by thegas tight sleeve to meet the gas tight ability.

Additionally, the gas tight assembly further comprises a fasteningcomponent. The fastening component is assembled to the sleeving end ofthe first sleeve and contacts an interior of the second sleeve. As aresult, the first sleeve and the second sleeve are stably connected toeach other and are hard to slide so as to prevent the first sleeve andthe second sleeve from disengagement.

Additionally, when the second sleeve is retracted, the second sleevemoves towards the handle portion, the first sleeve is retracted in thesecond sleeve until the gas tight assembly contacts the connection part.

In an embodiment, the grip comprises an opening. The openingcommunicates with the assembling channel, the first sleeve, and thesecond sleeve. A cutlery or another surgical instrument can be put inthe trocar set through the opening and can be further fixed in the firstsleeve and the second sleeve.

In an embodiment, the trocar set further comprises a second gas valve.The second gas valve is connected to the connection part andcommunicates with the first sleeve. Specifically, the second gas valveprovides greater amount of gas and has the gas flow into a human body tomake a portion of an internal space of a human body inflated, which isbeneficial of observing by an endoscope and performing an operation.

In another embodiment, a trocar set comprises a handle portion, a secondsleeve, and a gas tight assembly. The handle portion comprises a grip, aconnection part, and a second gas valve. The connection part extendsfrom the grip and comprises an assembling channel. The second gas valveis connected to the connection part and communicates with the assemblingchannel. The first sleeve comprises an assembling end and a sleevingend.

The assembling end is assembled to the assembling channel. The secondsleeve is retractably connected to the sleeving end of the first sleevesuch that the second gas valve, the assembling channel, the firstsleeve, and the second sleeve communicate with one another. The secondsleeve can be retracted relative to the first sleeve such that the firstsleeve can be received in the second sleeve, and the total length of thefirst sleeve and the second sleeve can be shortened. The gas tightassembly further comprises a blocking component and a gas tight sleeve.The blocking component is assembled to the first sleeve and is adjacentto the sleeving end. The gas tight sleeve is connected to a portionwhere the first sleeve is connected to the second sleeve. The gas tightsleeve encloses the blocking component.

In yet another embodiment, a trocar set comprises a handle portion, afirst sleeve, a second sleeve, a gas tight assembly, and a pulling band.The handle portion comprises a grip, a connection part, and a second gasvalve. The connection part extends from the grip and comprises anassembling channel. The second gas valve is connected to the connectionpart and communicates with the assembling channel. The first sleevecomprises an assembling end and a sleeving end. The assembling end isassembled to the assembling channel. The second sleeve is retractablyconnected to the sleeving end of the first sleeve such that the secondgas valve, the assembling channel, the first sleeve, and the secondsleeve communicate with one another. The second sleeve can be retractedrelative to the first sleeve such that the first sleeve can be receivedin the second sleeve, and the total length of the first sleeve and thesecond sleeve can be shortened. The gas tight assembly comprises afastening component and a gas tight sleeve. The fastening component isassembled to the sleeving end of the first sleeve and contacts aninterior of the second sleeve. The gas tight sleeve is disposed on apart of the first sleeve and the second sleeve and seals a portion wherethe first sleeve is connected to the second sleeve.

The pulling band crosses and is fixed to a portion connected to anexterior of the gas tight sleeve. The pulling band is adjacent to thefastening component.

According to embodiments of the trocar set of the instant disclosure,the trocar set is retractable by the connection of the first sleeve andthe second sleeve. When a cutlery is removed, the length of the trocarset outside the humane body can be significantly shortened so as toavoid the trocar set outside the human body being contacted by themedical professionals. The trocar set outside the human body beingcontacted may make a wound enlarged. Consequently, it is benefit tomedical professionals to perform operations.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a stereoscopic diagram of a trocar set in a stretchedstate according to a first embodiment;

FIG. 2 illustrates an exploded view of the trocar set according to thefirst embodiment;

FIG. 3 illustrates a cross-sectional view of the trocar set in thestretched state according to the first embodiment;

FIG. 4 illustrates a partial, cross-sectional view of the trocar set inthe stretched state according to the first embodiment;

FIG. 5 illustrates a stereoscopic diagram of the trocar set in thestretched state in use according to the first embodiment;

FIG. 6 illustrates a cross-sectional view of the trocar set in thestretched state according to the first embodiment;

FIG. 7 illustrates a partial, cross-sectional view of the trocar set ina retracted state in use according to the first embodiment;

FIG. 8 illustrates a partial, cross-sectional view of the trocar set inthe retracted state in use according to the first embodiment;

FIG. 9 illustrates a stereoscopic diagram of the trocar set in theretracted state according to the first embodiment;

FIG. 10 illustrates a stereoscopic diagram of a trocar set in theretracted state according to a second embodiment; and

FIG. 11 illustrates a stereoscopic diagram of the trocar set in thestretched state according to the second embodiment.

DETAILED DESCRIPTION

Please refer to FIG. 1 to FIG. 4, which are respectively a stereoscopicdiagram of a trocar set in a stretched state according to a firstembodiment, an exploded view of the trocar set according to the firstembodiment, a cross-sectional view of the trocar set in the stretchedstate according to the first embodiment, and a partial, cross-sectionalview of the trocar set in the stretched state according to the firstembodiment. As shown in FIG. 1 to FIG. 4, the trocar set 1 comprises ahandle portion 10, a first sleeve 20, a second sleeve 30, a gasbag 40,and a gas tight assembly 50. The handle portion 10 comprises a grip 11,a connection part 13, a first gas valve 15, and a second gas valve 17.The grip 11 may be, but not limited to, a semicircular shell structureof which an interior is hollow. The connection part 13 extends from thegrip 11 and is a column structure. The connection part 13 comprises anassembling channel 131. The assembly channel 131 is formed in a mannerof penetrating through the connection part 13. The assembling channel131 communicates with the interior of the grip 11. The first gas valve15 and the second gas valve 17 may be assembled to the connection part13. The first gas valve 15, the second gas valve 17, and the connectionpart 13 may be formed in one piece, alternatively. In addition, gas flowchannels of the first gas valve 15 and the second gas valve 17communicate with the assembling channel 131.

The first sleeve 20 comprises an assembling end 201 and a sleeving end203. The assembling end 201 is assembled to the assembling channel 131of the connection part 13. The first sleeve 20 extends from theassembling end 201 along a direction of a central axis of the assemblingchannel 131 and protrudes from the connection part 13. The first sleeve20 may be a double layer sleeve which comprises a first inner sleevewall 21 and a first outer sleeve wall 23. Specifically, the first sleeve20 defines a first sleeve wall region 211 and a second sleeve wallregion 213. The first outer sleeve wall 23 surrounds an exterior of thefirst inner sleeve wall 21 in the first sleeve wall region 211. Thefirst outer sleeve wall 23 does not surround the exterior of the firstinner sleeve wall 21 in the second sleeve wall region 213. The secondsleeve wall region 213 is in the assembling channel 131 and correspondsto the first gas valve 15. In addition, the first outer sleeve wall 23of the sleeving end 203 is provided with at least one first opening 231.In other words, gas introduced from the first gas valve 15 enters thefirst gas flow channel 25 through a region where the first outer sleevewall 23 does not surround the first inner sleeve wall 21 and leaves thefirst gas flow channel 25 from the first opening 231.

The second sleeve 30 comprises a receiving end 32. The sleeving end 203of the first sleeve 20 is inserted into the receiving end 32 of thesecond sleeve 30 such that the second sleeve 30 is retractably connectedto an end of the first sleeve 20 away from the handle portion 10. Thesecond sleeve 30 may be a double layer sleeve which comprises a secondinner sleeve wall 31 and a second outer sleeve wall 33. The secondsleeve 30 defines a third sleeve wall region 311, a fourth sleeve wallregion 313, and a fifth sleeve wall region 315. The second outer sleevewall 33, corresponding to the sleeving end 203, surrounds an exterior ofthe first outer sleeve wall 23 in the third sleeve wall region 311. Thesecond outer sleeve wall 33 surrounds an exterior of the second innersleeve wall 31 in the fourth sleeve wall region 313. The second outersleeve wall 33 does not surround the second inner sleeve wall 31 in thefifth sleeve wall region 315. A second gas flow channel 35 is formedbetween the second outer sleeve wall 33 and the second inner sleeve wall31. A region of the second outer sleeve wall 33 away from the sleevingend 203 is provided with at least one second opening 331. Specifically,an end of the second gas flow channel 35 corresponds to the firstopening 231. Gas from the first gas valve 15 is introduced through thefirst opening 231 and enters the second gas flow channel 35, and thenleaves the second gas flow channel 35 from the second opening 331.

The gasbag 40 is connected to an end of the second sleeve 30 away fromthe first sleeve 20. Particularly, the gasbag 40 is connected to a partof the second sleeve wall region 213 and connected to the third sleevewall region 311. The air cell 40 corresponds to the second opening 331.In other words, the region where the first outer sleeve wall 23 does notsurround the first inner sleeve wall 31, the first gas flow channel 25,the first opening 231, the second gas flow channel 35, and the secondopening 331 communicate with one another to form a gas flow channelcapable of inflating the gasbag 40. Gas introduced by the first gasvalve 15 enters the gasbag 40 through the aforementioned gas flowchannel to have the gasbag 40 inflated.

Please refer to FIG. 5 and FIG. 6, which are respectively a stereoscopicdiagram of the trocar set in the stretched state in use according to thefirst embodiment and a partial, cross-sectional view of the trocar setin the stretched state in use according to the first embodiment. Asshown in FIG. 1 to FIG. 6, the trocar set 1 in practical use isinstalled with a cutlery 200. The cutlery 200 is inserted into anopening 19 in a rear end of the handle portion 10 and is installed tothe grip 11, the connection part 13, the first sleeve 20, and the secondsleeve 30. The cutlery 200 protrudes from the second sleeve 30 and isfixed to the handle portion 10 by a rear cover 210. Additionally, thegrip 11 further comprises a first sealing component 117 and a secondsealing component 119. The cutlery 200 being installed may be assembledto and contact the first sealing component 117 and the second sealingcomponent 119. The first sealing component 117 and the second sealingcomponent 119 can seal the gas flow channel such that the cutlery 200having been fixed to the grip 11, the first sleeve 20, and the secondsleeve 30 can prevent the gas from leaking to meet the gas tightability.

As shown in FIG. 5 and FIG. 6, after the trocar set 1 in the stretchedstate is used to cut an opening on a human body 500, gas introduced fromthe first gas valve 15 may flow through the first gas flow channel 25,the first opening 231, the second gas flow channel 35, and the secondopening 331 and then enter the gasbag 40. When the gasbag is inflated,the trocar set 1 can be fixed in the human body 500. Further, the firstgas valve 15 may be a pressing type valve, which can inflate the gasbag40 by pressing.

Please refer to FIG. 7, FIG. 8, and FIG. 9, which are respectively apartial, cross-sectional view of the trocar set in a retracted state inuse according to the first embodiment, a cross-sectional view of thetrocar set in the retracted state according to the first embodiment, anda stereoscopic diagram of the trocar set in the retracted stateaccording to the first embodiment. As shown in FIG. 7, the cutlery 200can be removed from the trocar set 1 after the trocar set 1 is fixed tothe human body 500 by the gasbag 40. The trocar set 1 can be pushedforward by the handle portion 10 to have the second sleeve 30 movedtowards the handle portion 10 relative to the first sleeve 20, such thatthe first sleeve 20 can be retracted in the second sleeve 30 to be inthe retracted state. Therefore, the length of the trocar set 1 outsideof the human body 500 can be significantly shortened. Additionally, whenthe trocar set 1 is in the retracted stated, medical professionals mayconveniently put medical instruments such as an endoscope, an opticalfiber, or a laser into the human body along the first sleeve 20 and thesecond sleeve 30 and avoid contacting the trocar set 1. Additionally,the grip 11 comprises a butting block 113 capable of fixing medicalinstruments such as an endoscope, an optical fiber, or a laser.

Specifically, after the cutlery 200 is removed, gas can be inflated intothe human body from the second gas valve 17 through the first sleeve 20and the second sleeve 30 to have a human tissue expanded partially,which is beneficial of inserting medical instruments such as anendoscope, an optical fiber, or a laser, observing, and performing anoperation. Specifically, the second gas valve 17 can be a switch of gaswhich may be connected to an external inflating device for inflation.Additionally, after an operation is accomplished, the first gas valve 15can be turned on to have gasbag 40 deflated such that the trocar set 1can be removed from the human body, as shown in FIG. 8, and FIG. 9.

As shown in FIG. 1 to FIG. 4., the gas tight assembly 50 of the trocarset 1 is disposed on a portion where the first sleeve 20 and the secondsleeve 30 are connected to each other; therefore, the portion where thefirst sleeve 20 and the second sleeve 30 are connected to each other canbe sealed to prevent a gas leak. Specifically, the gas tight assembly 50further comprises a blocking component 51 and a gas tight sleeve 53. Theblocking component 51 is assembled to an exterior of the first sleeve 20and is adjacent to the sleeving end 203. The blocking component 51 isenclosed by the gas tight sleeve 53 to prevent the first sleeve 20 frombeing disengaged from the second sleeve 30. In an embodiment, the gastight sleeve 53 is a two piece combination. Specifically, when thetrocar set 1 is in the stretched state, the first opening 231 is betweenthe second outer sleeve wall 33 and the blocking component 51.

Additionally, as shown in FIG. 7, FIG. 8, and FIG. 9, when the trocarset 1 is retracted, the second sleeve 30 moves towards the handleportion 10 relative to the first sleeve 20 until the gas tight assembly50 contacts the connection part 13.

Additionally, the gas tight assembly 50 further comprises a gas tightring 55 and a fastening component 57. The gas tight ring 55 is connectedto the exterior of the first sleeve 20. In an embodiment, the gas tightsleeve 55 presses the gas tight ring 55 to have the gas tight ring 55tightly attach to the first sleeve 20 to meet the gas tight ability. Inan embodiment, the gas tight ring 53 contacts a surface of the blockingcomponent 51 and is enclosed by the gas tight sleeve 53. As shown in thedrawing, the gas tight ring 55 is, for example, on a surface of theblocking component 51 opposing the second outer sleeve wall 33. The gastight ring 55 may also be disposed on a surface of the blockingcomponent 51 facing the second outer sleeve wall 33. Alternatively, thegas tight ring(s) 55 may be disposed on both of the two surfaces of theblocking component 51. The fastening component 57 is disposed on thesleeving end 203 of the first sleeve 20. Particularly, the fasteningcomponent 57 encloses the sleeving end 203; therefore, the height of thesleeving end 203 is slightly greater than that of other regions of thefirst sleeve 20. The fastening component 57 contacts the second innersleeve wall 31 of the second sleeve 30. Due to the fastening component57, the second sleeve 30 may slide relative to the first sleeve 20 so asto stretch or to retract only when the second sleeve 30 is forced. As aresult, the first sleeve 20 and the second sleeve 30 are steady afterbeing stretched or retracted and are hard to slide so as to prevent thefirst sleeve 20 and the second sleeve 30 from disengagement.

Please refer to FIG. 10 and FIG. 11, which are stereoscopic diagrams ofa trocar set in the retracted state and in the stretched staterespectively according to a second embodiment. As shown in FIG. 10 andFIG. 11, a difference between the first embodiment and the secondembodiment is that the trocar set 1 does not have the gasbag 40 and thefirst gas valve 15. Although the trocar set 1 cannot be fixed to a humanbody by the gasbag, the trocar set 1 can be stably set by a stand orother measures after penetrating and allow instruments to be insertedthere through. In order to prevent a gas leak, it is merely requiredthat the gas tight assembly 50 is connected to a portion where the firstsleeve 20 and the second sleeve 30 are connected to each other. As aresult, there may be no need of the structure of the double layersleeve, and, consequently, the cost may be lower. The gas tight assembly50 may comprise the blocking component 51 and the gas tight sleeve 53and may further comprise the gas tight ring 55 and the fasteningcomponent 57.

Additionally, as shown in FIG. 1, FIG. 5, FIG. 9, and FIG. 11, thetrocar set 1 further comprises at least one pulling band 60. The pullingband 60 is at an exterior of the gas tight assembly 50 and is adjacentto the fastening component 57. An outer wall of the gas tight sleeve 53is provided with two crossing channels 531, which do not penetratethrough the gas tight sleeve 53. The pulling band 60 crosses thecrossing channels 531 to form a closed loop structure. When the firstsleeve 20 is forced to be retracted in the second sleeve 30, and thepulling band 60 is accordingly forced towards outside, an inward forceand an outward force can be balanced and then the position of the secondsleeve 30 can be stably fixed. In an embodiment, a pulling band setcomprising two pulling bands symmetric to each other may be adopted. Forexample, the pulling band 60 may be, but not limited to, fixed to theconnection part 13. In a state as shown in FIG. 5, the pulling band 60can be pulled after the gasbag 40 is inflated to make sure that thetrocar set 1 is fixed to a human body. Or, the pulling band 60 may bepulled after the surgery to assist in removing the trocar set 1 from thehuman body. Additionally, in the first embodiment, the gasbag has to bedeflated in advance such that the trocar set can be removed by thepulling band 60 after a surgery.

According to embodiments of the trocar set of the instant disclosure,the trocar set is retractable by the connection of the first sleeve andthe second sleeve. When the cutlery is removed from the trocar set, thefirst sleeve can be retracted in the second sleeve; therefore, thelength of the trocar set outside of a humane body can be significantlyshortened so as to avoid the trocar set being unintentionally contactedby medical professionals. A trocar set outside of the humane body beingcontacted may cause pain and make a wound enlarged. Consequently, it isbenefit to medical professionals to insert instruments and performoperations.

While the instant disclosure has been described by way of example and interms of the preferred embodiments, it is to be understood that theinstant disclosure needs not be limited to the disclosed embodiments.For anyone skilled in the art, various modifications and improvementswithin the spirit of the instant disclosure are covered under the scopeof the instant disclosure. The covered scope of the instant disclosureis based on the appended claims.

What is claimed is:
 1. A trocar set, comprising: a handle portioncomprising a grip, a connection part, and a second gas valve, whereinthe connection part extends from the grip and comprises an assemblingchannel, and the second gas valve is connected to the connection partand communicates with the assembling channel; a first sleeve comprisingan assembling end, a sleeving end, a first outer sleeve wall, and afastening component, wherein the assembling end is assembled to theassembling channel, and the fastening component is disposed at thesleeving end and contacts the first outer sleeve wall; a second sleevecomprising a receiving end and a second inner sleeve wall, wherein thesleeving end is inserted into the receiving end, and the second innersleeve wall contacts the fastening component; a gas tight assemblycomprising a gas tight sleeve and a blocking component, wherein the gastight sleeve is fixed to the second sleeve and encloses the receivingend and the blocking component, the blocking component restricts anaxial displacement of the fastening component such that the first sleevecannot be disengaged from the second sleeve, and an outer wall of thegas tight sleeve is provided with a plurality of crossing channels andthe crossing channels are not in a through-hole type; and a pulling bandcrossing the crossing channel.
 2. The trocar set of claim 1, wherein thepulling band is forced towards outside to fix the second sleeve whilethe first sleeve is forced to be retracted in the second sleeve.
 3. Thetrocar set of claim 2, further comprising a gas tight ring, the gastight ring being connected to a part of the first sleeve and beingadjacent to the blocking component.